A microstrip leaky wave antenna radiates energy from a microstrip line on top of a dielectric substrate. The principle of this antenna is that a wave guided by the microstrip will “leak” or produce a radiated field within a certain frequency range. The radiation is dominated by a main beam, the direction of which is determined by the phase constant of the propagating wave. Since the propagation constant is frequency dependent, as the operating frequency is changed, the direction of the main beam also changes. Thus, the direction of the main beam cannot be controlled after the initial design except by changing the frequency. Although this frequency scanning characteristic makes leaky-wave antennas attractive for certain applications, fixing the main beam at particular frequencies would allow for other applications of the antenna whereby its other attractive attributes could be exploited (e.g., ease of fabrication, conformability and reasonable cost).
Therefore, it is desirable to achieve a leaky wave antenna configurable dynamically to output one or more main beams at user selectable angles while maintaining a fixed frequency. This section provides background information related to the present disclosure which is not necessarily prior art.